Classic graveyard. Gravestones, a cross or two and a skull, half sunk into the moss as if they have been there for years. The Haunted Cemetery set is built for exactly this and gives you enough pieces to fill a mid-sized terrarium on its own.

Quiet and understated. A single small skull or two tucked into the moss, no scene, no story, just a hint of something odd if you look closely. Skulls Gone Wild works well here since the set gives you enough variety to use two or three and save the rest for next year.

Night mode. Built entirely around the glow-in-the-dark effect, using Spooky Squad or the Halloween spooky crew. Charge them under a lamp during the day, then switch off the room lights on the evening of the 31st and let the terrarium do the work.

Trick-or-treat village. A tiny black cat, a raven, a ghost and a small haunted house arranged like a miniature street scene, using the Trick or Treat Village set. This one works best in a wider terrarium or an open bowl, since the pieces are meant to be spread out rather than clustered.

Pumpkin patch with a twist. Mix the Pumpkin monsters mini figures in with a couple of the lightweight foam pumpkins from our pumpkin decoration range for something that reads as autumn first and Halloween second, useful if you want the terrarium to still look right through the rest of November.

Most of these miniatures measure between 1 and 4 cm, so they pass through the neck of a standard terrarium bottle without trouble, and sit comfortably in anything from around 15 cm wide upward. A narrow-necked bottle such as a Sam or Fat Joe style jar takes one or two pieces at a time, placed with tweezers. A wide dome, an open bowl or a jar without a narrow neck lets you build a fuller scene by hand and is the easier starting point if this is your first one. Check the size listed on each product before you buy if you are working with a particularly narrow bottle.

Keeping the plants healthy while it is spooky

None of this decoration is a problem for a healthy plant over the two or three weeks it is likely to stay in place. A few habits keep it that way. Rest figures on moss or soil rather than directly on leaves, so nothing traps moisture against the plant. Do not block the main light source with a tall piece, particularly in a smaller terrarium where every bit of light matters. If your terrarium is closed, open the lid for a few minutes after adding decoration, the same way you would after watering, so any extra humidity from handling has somewhere to go. And check the plant as normal during this period. If a leaf looks stressed, it is almost always the plant telling you something about light or moisture rather than the decoration itself.